Japanese National Patent Publication No. 2015-520661 (PTD 1) describes that a construction having a superhard structure, which is to be processed into a cutting blade of a rotary cutting tool, is attached to a tool carrier. Specifically, attaching means such as a thread groove for brazing the above-described construction and the tool carrier is, for example, provided in the above-described construction, which makes it possible to attach the above-described construction to the tool carrier.